Resectoscope comprisig positioned optics

ABSTRACT

A urological resectoscope is disclosed, having a tubular shaft ( 1 ), through which an optical system ( 2 ) and a longitudinally moveable instrument carrier ( 5 ) pass. The optical system ( 2 ) is supported with respect to the tubular shaft ( 1 ) at a spacing from the proximal end of the tubular shaft ( 1 ) with a support device ( 9, 12 ). The carrier ( 5 ) is positioned with a radial positioning device ( 10, 15 ) and a circumferential angular positioning device ( 11, 12 ). The support device ( 12, 18, 18′ ) is so arranged adjacent to the optical system ( 2 ) in the region in which the carrier ( 5 ) extends, that it supports the optical system ( 2 ) with respect to the tubular shaft ( 1 ) with a two point support system and imparts lateral guidance to the carrier ( 5 ) in the circumferential angular direction.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a urological resectoscope of the type having atubular shaft through which an optical system and a longitudinallymoveable instrument carrier pass.

2. Description of Related Art

Resectoscopes constitute the principal device in urological surgery andare used, in particular, for prostate resections. They may also be usedin gynaecology. As the instrument they have a knife or generally theconventional cutting loop, to which high frequency may be applied, whichmay be advanced forwardly beyond the tubular shaft. The instrument isused in the region in front of the distal end of the tubular shaftwhilst optically viewing through the optical system. The tubular shaftcan be a simple tube or can consist of an outer shaft and an innershaft, when the resectoscope is constructed in the form of a continuousflow resectoscope, the optical system and the elongate instrumentcarrier carrying the instrument at its distal end being arranged withinthe inner shaft.

Provided at the proximal end of the potentially multi-tube shaft, whichmay commonly may be decoupled, is an operating device, starting fromwhich the optical system, which is commonly replaceable, may be slidinto the system, and which is engaged by the hand of the user. A slidingcarriage is also provided there in the conventional construction, towhich the proximal end of the instrument carrier is fastened in orderthat it may be longitudinally moved and to which current may be applied,if it is a high frequency operated instrument.

Precise positioning of the instrument in the radial and rotationaldirection is of importance in resectoscopes for a precise mode ofoperation. Furthermore, the optical system must be held in apredetermined position in order to ensure a reproducible viewing angle.

The known construction of resectoscopes of the type referred to above,which is currently common in the art, is illustrated in FIG. 1.

Only the distal end region of the shaft is shown with a tubular shaft 1and an optical system 2 with an objective 3 and with an optical guidetube 4, which guides the optical system over a proportion of the lengthof the tubular shaft 1. The optical guide tube 4 extends, in theconventional construction, through the main body, not shown, of theresectoscope, to which the tubular shaft 1 may be coupled, and extendsthrough the operating device and commonly through the sliding carriageprovided there.

An instrument carrier 5 (referred to below as the carrier), which isconstructed in the form of an elongate rod, extends at its proximal endto the sliding carriage, which is not shown, with which it is connectedand in electrical contact. It extends straight through the tubular shaft1 to a branch point 6, at which it branches to form a fork 7, the twobranches of which extend laterally around the optical system 2 and carrythe cutting loop 8, to which high frequency may be applied, at theirends, instead of which a knife can also be provided as an instrument inanother embodiment.

In the conventional construction of known resectoscopes, the illustratedtubular shaft 1 is the inner shaft of a shaft system with two concentricshafts. Also provided on the shafts in the distal end region is anannular insulating body. Flushing liquid is conducted through proximallydisposed flushing connections which are not shown, to the interior ofthe tubular shaft 1 and is drained away by suction through the spacebetween the two tubular shafts.

With regard to the positioning problem outlined above, the known priorart provides the following as shown in FIG. 1:

The optical guide tube 4 is supported with respect to the tubular shaft1 with a nose 9, which is connected in the exemplary construction, to aguide tube 11, which for its part is connected to the optical guide tube4.

The exact positioning of the instrument, that is to say of the cuttingloop 8, is effected (with polar co-ordinates seen in the cross sectionof the tubular shaft 1) by a radial positioning device and acircumferential angular positioning device, which are separatelyconstructed in the prior art. Secured to the carrier 5 is a sliding tube10 constituting the radial positioning device, which is slideably guidedon the optical system 2 and thus ensures the radial distance between theprecisely positioned optical system 2 and the carrier 5.

The guide tube 11, through which the carrier 5 passes, serves as thecircumferential angular positioning device and holds it at a fixedcircumferential angle.

This known construction has disadvantages, particularly as regards theguide tube 11, which is difficult to clean as a result of its smalldiameter. Furthermore, the optical guide tube 4 is absolutely necessaryfor the mounting of the guide tube 11 and the nose 9, which positionsthe optical system. As a result of the optical guide tube 4, the overallconstruction of the resectoscope is made more expensive and cleaningproblems are produced as regards also the narrow guide tube 11.

DE 19631677 C1 discloses an endoscope of a type completely different tothat referred to above, which serves to sever perforated veins whenremoving varicose veins in the leg. Disposed in a tubular shaft of verylarge diameter is an optical system, which is supported by means of aramp in order to secure its position. As a result of the particularfeatures of this special construction, no suggestion can be derived forthe construction of resectoscopes.

SUMMARY OF THE INVENTION

The object of the present invention resides in simplifying aresectoscope of the type referred to above structurally and as regardsthe cleaning problems.

In accordance with the invention, the optical system is supported in theangular range of the carrier with respect to the tubular shaft with atwo-point support system, whereby it is reliably positioned. The supportcan advantageously be effected such that the optical system is pressedagainst the tubular shaft at a third, opposite position so that it issituated in a precise three-point positioning system. The support deviceimparts lateral guidance to the carrier in order to prevent variationsin the circumferential angular direction. For its radial positioning,the carrier can be guided in the conventional manner, for instance asillustrated in FIG. 1, with the sliding tube 10 on the optical system 2.The guide tube 11 is omitted in the construction in accordance with theinvention with its cleaning problems. The entire optical guide tube canalso be saved. The possibility is also produced by comparison with theprior art, as is illustrated in FIG. 1, of arranging the entirepositioning device of the optical system and the carrier closer to thedistal end of the tubular shaft and thus with a better positioningaction on the instrument itself.

Two fixed angular positioning webs in lateral sliding contact with thecarrier produce a good circumferential angular positioning of thecarrier and thus of the instrument and a reliable two point positioningof the optical system with respect to the tubular shaft.

The webs can be constructed in the interior of the tubular shaft on thelatter, e.g. by soldering or by the formation of indentations on thetubular shaft. A very simple and precisely positioning construction isthus produced.

As already mentioned, the optical guide tube can be saved in accordancewith the invention. If, however, an optical guide tube is present forother reasons, then the webs are fastened to the optical guide tube andsupport the latter, and thus the optical system, with respect to thetubular shaft. This construction has the advantage that a smooth,conventional tubular shaft may be used.

As already mentioned, the webs serve to guide the carrier in thecircumferential direction. For the purpose of radially guiding thecarrier, it can be guided on the optical system in the known manner withthe sliding tube. Advantageously, however, the webs are so constructedthat they guide the carrier in its radial position also with guideprofiles. The sliding tube on the carrier can then be omitted.

The carrier can be guided directly on the webs in its rod-shapedconstruction. Preferably, however, strips are provided on the carrier inthe length region, in which it comes into contact with the webs, whichensure sliding contact with the webs. Particularly precise slidingcontact can be ensured with the strips, particularly if a profiledengagement is necessary.

As already mentioned, the support device can be provided connected tothe tubular shaft e.g. in the form of webs, or alternatively connectedto the optical guide tube, if one is present. Alternatively, the supportdevice is connected to the carrier. Changes to the resectoscope are thussuperfluous. The support device again supports the optical system withrespect to the tubular shaft and imparts guidance to the carrier in theperipheral angular direction. In the event of longitudinal movement ofthe carrier, it slides on the optical system and the tubular shaftwhilst maintaining the guidance.

The non-circular peripheral profile of the tubular shaft results in aprecise angular positioning of the support device sliding in profiledengagement with the tubular shaft and thus in a better circumferentialangular guidance of the carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the known construction of resectoscopes which is currentlycommon in the art,

FIG. 2 is a longitudinal sectional view corresponding to FIG. 1 of aresectoscope in accordance with the invention,

FIGS. 3-5 are sectional views on the line 3-3 in FIG. 2 of differentembodiments,

FIG. 6 is a sectional view corresponding to FIG. 2 of a furtherembodiment,

FIG. 7 is a sectional view on the line 7-7 in FIG. 6 and

FIG. 8 is a view corresponding to FIG. 7 of a further embodiment.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 2 and 3 show a first embodiment of the invention corresponding tothe extent possible with FIG. 1 and using, to the extent possible, thesame reference numerals. The tubular shaft 1 or the inner shaft of amulti-tube resectoscope is again shown. The carrier 5, whichsubstantially corresponds to that in FIG. 1, is guided in the samemanner in this embodiment at a radial spacing on the optical system 2with the sliding tube 10, as in the known construction of FIG. 1.

The construction of FIG. 2 has no optical guide tube. The support of theoptical system 2 with respect to the tubular shaft 1 is effected bymeans of two webs 12, as is shown in the sectional view on the line 3-3in FIG. 3. The webs extend in the radial direction between the opticalsystem 2 and the tubular shaft 1 and are constructed integrally with thetubular shaft 1 in the exemplary embodiment of FIGS. 2 and 3. As shownin FIG. 3, a reliably positioning engagement for the optical system 2 isproduced. The webs 12 can also be soldered to the tubular shaft orformed on it in the form of indentations.

As shown in FIG. 3, the carrier 5 extends between the webs 12 and ispositioned by it in the circumferential angular direction. For thispurpose, the carrier 5 has lateral strips 13 in its longitudinaldisplacement region, with which is engages the two webs 12.

FIG. 3 a shows a structural variation to FIG. 3, in which the two webs12 are connected to inner and outer shells 17 to form a tubular platebody, which is closed in the cross section of FIG. 3 a and is secured tothe tubular shaft 1 by soldering or in some other manner and which, asmay be seen, fulfils the same supporting function as shown in FIG. 3.The carrier 5, which is not shown in FIG. 3 a, can be laterallysupported in the same manner as shown in FIG. 3.

FIG. 4 shows a structural modification to the embodiment to FIGS. 2 and3, in which the optical guide tube 4, which may be seen in FIG. 1, isprovided. The webs 12 are secured in this case, as shown in FIG. 4, tothe optical guide tube 4 and engage the tubular shaft 1 in a reliablysupportive manner. The carrier 5 is supported in the peripheraldirection between the webs 12, as shown in FIG. 3. The tubular shaft 1can be constructed in this case as a continuously smooth tube.

If one compares the embodiments of FIG. 3 and FIG. 4, it will be seen ina further comparison with FIG. 1 that in the embodiment of FIG. 3 thereis not only the advantage that no optical guide tube 4 is necessary butalso the advantage that the circumferential angular positioning of thecarrier 5 can be effected not on the optical guide tube, that is to sayrelatively remote from the distal end of the tubular shaft 1, butfurther forwards in the region of the sliding tube 10, that is to saywith a better positioning effect on the cutting blade 8.

FIG. 5 shows a further alternative embodiment, whereby it isadditionally illustrated in this case for explanatory purposes that thetubular shaft 1 can be an inner shaft, which is surrounded by an outershaft 14.

FIG. 5 again shows webs 12, which are connected to the tubular shaft inaccordance with the embodiment of FIG. 3 and supportingly engage theoptical system 2. However, in the embodiment of FIG. 5, the webs are ofkinked shape with an angular profile 15 extending in the longitudinaldirection of the shaft, in which the strips 13 of the carrier aresubjected to precise guidance, which reliably guides the carrier 5 notonly in the circumferential angular position but also in the radialspacing from the optical system 2. The sliding tube 10 illustrated inFIGS. 1 and 2 can be omitted in this construction.

In the embodiments illustrated in FIGS. 3 to 5, the carrier 5 ispositioned against the webs 12 with strips 3. The webs 12 can, however,can also be positioned closer together so that they exactly guide thecarrier 5 directly, that is to say without strips 13.

In the illustrated embodiments, the optical system is positioned againstthe webs 12 with a two point engagement with bending stressing of theoptical system or, as shown in FIG. 4, with stressing also of theoptical guide tube 4. It can be held by the webs 12 against the oppositeinner surface of the tubular shaft 1, as illustrated in FIGS. 2 and 6with the contact point 16 and as indicated in FIG. 3 with 2′. There isthen a precisely positioning three point engagement. FIGS. 6 and 7 showanother embodiment, in which, instead of the previously described webs12, a support device 18 is provided which is shown in the form of ablock with a profiled periphery, which is secured to the carrier 5 andmoves in sliding contact with the optical system 2 and the inner surfaceof the tubular shaft 1 with longitudinal movement of the carrier 5. Asshown in FIG. 7, the support device 18 is in two point engagement withthe optical system 1 and also in two point engagement with the tubularshaft 1 and basically imparts to the optical system 2 the same two pointsupport with respect to the tubular shaft 1, as is illustrated in e.g.FIG. 3. It also ensures that the carrier 5 has good lateral support and,as shown in FIG. 7 and indicated with the contact point 16 in FIG. 6,presses the optical system 1 at a third engagement point against thetubular shaft 1 to produce a reliable three point support system.

As a modification of FIG. 7, FIG. 8 shows a structural variant, in whichthe tubular shaft 1′ is of non-circular profile in the illustratedmanner. The support device 18′ is constructed in the form of a tubularbody with a profiled periphery, through which the carrier 5 extends. Thesupport device 18′ is connected by means, which are not illustrated, tothe carrier 5, for instance by adhesive, clamping or the like. Theperiphery of the support device 18′ is so profiled to match the profileof the tubular shaft 1′ that good angular positioning is produced, as isshown in FIG. 8.

1. A urological resectoscope including a tubular shaft (1), throughwhich an optical system (2) and a longitudinally moveable instrumentcarrier (5) pass, the optical system (2) being supported with respect tothe tubular shaft (1) at a spacing from the proximal end of the tubularshaft (1) with a support device (9, 12) and the carrier (5) beingpositioned with a radial positioning device (10, 15) and acircumferential angular positioning device (11, 12), wherein the supportdevice (12, 18, 18′) is so arranged adjacent to the optical system (2)in the region in which the carrier (5) extends, that it supports theoptical system (2) with respect to the tubular shaft (1) with a twopoint support system and imparts lateral guidance to the carrier (5) inthe circumferential angular direction.
 2. The resectoscope as claimed inclaim (1), wherein the support device (12, 18, 18′) is so constructedthat it brings the optical system (2) into engagement with the side ofthe tubular shaft (1) situated opposite to the support device (12, 18,19′) in a three point support system.
 3. The resectoscope as claimed inclaim 1, wherein the support device has two circumferentially spaced,fixed webs (12), which are each arranged in contact with the opticalsystem (2) and the tubular shaft (1) on both sides of the carrier (5)and in sliding contact with it.
 4. The resectoscope as claimed in claim1, wherein the webs (12) are connected to the tubular shaft (1).
 5. Theresectoscope as claimed in claim 1, including an optical guide tube (4)accommodating the optical system (2), at least in the proximal region ofthe tubular shaft (1), wherein the webs (12) are connected to theoptical guide tube (4).
 6. The resectoscope as claimed in claim 1,wherein the webs (12) have guide profiles (15) extending parallel to thetubular shaft (1) for longitudinally moveably guiding the carrier (5) ina radially fixed position.
 7. The resectoscope as claimed in claim 1,wherein the carrier (5) has strips (13) contacting the webs (12) in itslongitudinal region, with which it is longitudinally moveable on thewebs (12).
 8. The resectoscope as claimed in claim 1, wherein thesupport device (18, 18′) is connected to the carrier (5) and isconstructed to slide on the optical system (2) and on the tubular shaft(1, 1′).
 9. The resectoscope as claimed in claim 8, wherein the tubularshaft (1′) has a non-circular cross section matching the circumferentialprofile of the support device (18′).